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HD 50281
Observation data
Epoch J2000       Equinox J2000
Constellation Monoceros
Right ascension 06h 52m 18.05045s [1]
Declination −05° 10′ 25.36617″ [1]
Apparent magnitude (V) 6.58 [2]
Characteristics
Evolutionary stage main sequence
Spectral type K3.5 V [3]
B−V color index 1.071±0.008 [2]
Astrometry
Radial velocity (Rv)−7.20±0.15 [4] km/s
Proper motion (μ) RA: −543.616 [1]  mas/ yr
Dec.: −3.491 [1]  mas/ yr
Parallax (π)114.2968 ± 0.0465  mas [1]
Distance28.54 ± 0.01  ly
(8.749 ± 0.004  pc)
Absolute magnitude (MV)6.87 [5]
Details
Mass0.79 [6]  M
Radius0.73+0.01
−0.02
[1]  R
Luminosity0.225 [1]  L
Surface gravity (log g)4.64 [6]  cgs
Temperature4,712±8.5 [7]  K
Metallicity [Fe/H]+0.01 [8]  dex
Rotational velocity (v sin i)5.5 [6] km/s
Age1.88 [6]  Gyr
Other designations
88 G. Monocerotis, BD−05°1844, GJ 250, HD 50281, HIP 32984, HR 2534, SAO 133805, WDS J06523−0510, LFT 494, LHS 1875, LTT 2662 [9]
Database references
SIMBAD A
B

HD 50281 is a star in the equatorial constellation of Monoceros. It is orange in hue with an apparent visual magnitude of 6.58, [2] which lies at or below the typical limit of visibility to the naked eye. The star is located at a distance of 28.5  light years from the Sun based on parallax, but is drifting closer with a radial velocity of −7.2 km/s. [4]

This object is an ordinary K-type main-sequence star with a stellar classification of K3.5 V. [3] It is nearly two billion years old and is spinning with a projected rotational velocity of 5.5 km/s. [6] The metallicity of this star – what astronomers term the abundance of elements with atomic numbers greater than helium – is near solar. The star has 79% [6] of the mass of the Sun and 73% [1] of the Sun's radius. It is radiating 22.5% [1] of the luminosity of the Sun from its photosphere at an effective temperature of 4,712 K. [7]

A magnitude 10.16 common proper motion companion, [10] designated component B, is located at an angular separation of 58.8 along a position angle of 181° from the primary, as of 2015. [10] This is a suspected binary star system [11] with components of individual visual magnitude 10.6 and 11.1, [10] and a class of M2.5 V. [12] The coordinates of this companion are a source of X-ray emission. [13] A third companion, magnitude 14.04 component C, lies at a separation of 9.6″ from component B. [10]

References

  1. ^ a b c d e f g h i Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID  119257644.
  3. ^ a b Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal. 132 (1): 161–170. arXiv: astro-ph/0603770. Bibcode: 2006AJ....132..161G. doi: 10.1086/504637. S2CID  119476992.
  4. ^ a b Bailer-Jones, C.A.L.; et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics. 616: A37. arXiv: 1805.07581. Bibcode: 2018A&A...616A..37B. doi: 10.1051/0004-6361/201833456. S2CID  56269929.
  5. ^ Holmberg, J.; et al. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics. 501 (3): 941–947. arXiv: 0811.3982. Bibcode: 2009A&A...501..941H. doi: 10.1051/0004-6361/200811191. S2CID  118577511.
  6. ^ a b c d e f Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv: 1611.02897. Bibcode: 2017AJ....153...21L. doi: 10.3847/1538-3881/153/1/21. S2CID  119511744. 21.
  7. ^ a b Kovtyukh, V. V.; et al. (2003). "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios". Astronomy and Astrophysics. 411 (3): 559–564. arXiv: astro-ph/0308429. Bibcode: 2003A&A...411..559K. doi: 10.1051/0004-6361:20031378. S2CID  18478960.
  8. ^ Rojas-Ayala, Bárbara; et al. (April 2012). "Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs" (PDF). The Astrophysical Journal. 748 (2): 93. arXiv: 1112.4567. Bibcode: 2012ApJ...748...93R. doi: 10.1088/0004-637X/748/2/93. S2CID  41902340.
  9. ^ "HD 50281". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-06-06.
  10. ^ a b c d Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode: 2001AJ....122.3466M. doi: 10.1086/323920.
  11. ^ Mason, Brian D.; et al. (May 2018). "Speckle Interferometry of Red Dwarf Stars". The Astronomical Journal. 155 (5): 14. arXiv: 1804.07845. Bibcode: 2018AJ....155..215M. doi: 10.3847/1538-3881/aab9b8. S2CID  119267352. 215.
  12. ^ Kirkpatrick, J. D.; et al. (1991). "A standard stellar spectral sequence in the red/near-infrared - Classes K5 to M9". Astrophysical Journal Supplement Series. 77: 417. Bibcode: 1991ApJS...77..417K. doi: 10.1086/191611.
  13. ^ Johnson, H. M. (April 1986). "An Unbiased X-Ray Sampling of Stars within 25 Parsecs of the Sun". Astrophysical Journal. 303: 470. Bibcode: 1986ApJ...303..470J. doi: 10.1086/164092. hdl: 2060/19860004737.

External links